What is a synovial biopsy?

A synovial biopsy is a minimally invasive procedure that helps diagnose joint problems. This includes inflammatory conditions, infections, arthritis, cancer, and autoimmune disorders. Your doctor uses either a needle or an arthroscope to remove a sample of joint tissue. An arthroscope has a tiny camera that allows your doctor to view the inside of a joint. Your doctor will send the joint tissue sample to a lab for testing. 

Synovial biopsy is a minor procedure, but it involves some risk and potential complications. You may have less invasive diagnostic options. Consider getting a second opinion about all of your diagnostic options before having a synovial biopsy. 

Why is a synovial biopsy performed? 

Your doctor may recommend a synovial biopsy to help diagnose joint problems when a cause is not clear. A synovial biopsy is not a routine diagnostic procedure. Your doctor will only consider a synovial biopsy when other methods cannot find the cause of joint problems. Ask your doctor about all of your testing options before deciding on a synovial biopsy.

Your doctor may recommend synovial biopsy to diagnose the following conditions: 

  • Arthritis, including osteoarthritis and gout
  • Autoimmune disorders, including rheumatoid arthritis and lupus
  • Cancer, including synovial cancer and leukemic arthritis
  • Joint infections, also called septic arthritis
  • Metabolic diseases, including hemochromatosis, which leads to abnormal iron deposits

Who performs a synovial biopsy?

Orthopedic surgeons and rheumatologists perform synovial biopsies. Orthopedic surgeons are specially trained to treat problems of the bones and joints. They perform surgery and prescribe other treatments. Rheumatologists specialize in diagnosing and treating arthritis and other rheumatic diseases. Rheumatic diseases affect your joints, tendons, ligaments, bones and muscles.

How is a synovial biopsy performed?

Your synovial biopsy will be performed in a hospital or outpatient setting. It involves inserting either a needle or an arthroscope into your joint and removing a sample of tissue. 

A needle biopsy involves inserting a needle into the joint to take the tissue sample. Your doctor may use ultrasound to help guide the needle placement. 

Arthroscopy involves making at least two small incisions in the joint. Your doctor will insert an arthroscope and special instruments through the incisions. A tiny camera on the arthroscope allows your doctor to view the inside of your joint on a video screen. This helps your doctor to take a tissue sample from a very precise location in your joint. 

Types of anesthesia 

Your doctor will perform your synovial biopsy using general anesthesia, regional anesthesia, or local anesthesia. 

  • General anesthesia is a combination of intravenous (IV) medications and gases that put you in a deep sleep. You are unaware of the procedure and do not feel any pain. 
  • Local anesthesia involves injecting the anesthetic in the skin and tissues around the procedure area. You will likely have sedation with local anesthesia to keep you relaxed and comfortable.
  • Regional anesthesia is also known as a nerve block. It involves injecting an anesthetic around certain nerves to numb a large area of your body. You will likely have sedation with regional anesthesia to keep you relaxed and comfortable.

What to expect the day of your synovial biopsy

The day of your biopsy, you can expect to:

  • Talk with a preoperative nurse. The nurse will perform an exam and ensure that all needed tests are in order. The nurse can also answer questions and will make sure you understand and sign the procedure consent form.
  • Remove all clothing and jewelry and dress in a hospital gown. It is a good idea to leave all jewelry and valuables at home or with a family member. The procedure team will give you blankets for modesty and warmth.
  • Talk with the anesthesiologist or nurse anesthetist about your medical history and the type of anesthesia you will have.
  • A surgical team member will start an IV.
  • The anesthesiologist or nurse anesthetist will start your anesthesia.
  • A tube may be placed in your windpipe to protect and control breathing during general anesthesia. You will not feel or remember this or the surgical procedure as they happen.
  • The procedure team will monitor your vital signs and other critical body functions. This occurs throughout the surgery and during your recovery until you are alert, breathing effectively, and your vital signs are stable.